Modern aircraft gas turbine engines utilize sophisticated control systems to optimize engine performance and efficiency and remove, as much as possible, work load from the pilot. These control systems require input concerning various engine and environmental parameters for accurate, optimal functioning. In addition, many engine parameters require monitoring to inform the pilot of the correct functioning of the various engine systems and to warn maintenance personnel of any impending system failure or need for maintenance.
Conventional sensing systems include measuring devices positioned at numerous locations about the engine for monitoring the various engine parameters. Electronic transducers or switches associated with the various measuring devices generate electric signals which are conducted along electric cables to the engine control system or monitors. Each switch or transducer may require that two or more wires be routed to it along with associated connectors, connector backshells, harness shielding and lightning protection devices.
The present invention greatly reduces the need for heavy, expensive electrical hardware by substitution of a minimum number of fiber optic devices and cabling. Fiber optic devices are advantageous due to their resistance to the adverse effects of electromagnetic interference and lightning. In addition, a single optic fiber cable can function to transmit a multitude of signals of different frequencies or to transmit signals in opposite directions along the cable without impairment to any of the signals. Thus, the advantages of the present invention are in the elimination of external wiring on the engine, the elimination of electrical cable shielding and lightning protection, reduction in system weight, and circuit simplification.